install-includes is ignored in foreign-library target.

[qnikst]

install-includes field is only processed for the library target. And it doesn't work for foreign-library:

Minimal example:

foreign.cabal:

-- Initial foreign.cabal generated by cabal init.  For further 
-- documentation, see http://haskell.org/cabal/users-guide/

name:                foreign
version:             0.1.0.0
synopsis:            An example of the foreign library.
description:         Foreign library example, this project is done as
                     a simple test of the foreign libraries inclusion.
license:             BSD3
license-file:        LICENSE
author:              Alexander Vershilov
maintainer:          [email protected]
build-type:          Simple
extra-source-files:  ChangeLog.md
cabal-version:       >=2.0

-- uncomment to fix an issue:
--library
--  build-depends:       base >=4.9 && <4.10
--  hs-source-dirs:      src
--  other-modules:       Lib
--  install-includes:    Lib_stub.h  
--  default-language:    Haskell2010
 

foreign-library      mylib
  type:              native-shared
  lib-version-info:  6:3:2
  build-depends:       base >=4.9 && <4.10
  hs-source-dirs:      src
  other-modules:       Lib
  install-includes:    Lib_stub.h
  other-extensions:    ForeignFunctionInterface
  default-language:    Haskell2010

src/Lib.hs

{-# LANGUAGE ForeignFunctionInterface #-}
module Lib
  ( fac1
  ) where

foreign export ccall fac1 :: Int -> Int

fac1 :: Int -> Int
fac1 n = product [1..n]

Relevant call in codebase:

cabal/Cabal/Distribution/Simple/Install.hs

Line 173 in 6814d87

installIncludeFiles verbosity lib lbi buildPref incPref

[23Skidoo]

Fixed by #5302.